Printing plate cylinder and method of mounting or demounting same from a mandrel



Aprll 9, 1957 J. F. KIRBY ET AL 2,787,956

PRINTING PLATE CYLINDER AND METHOD OF MOUNTING OR DEMOUNTING SAME FROM A MANDREL Filed July 28, 1953 2 Sheets-Sheet l m 'EX TOR. 19 JOHN F K/EBY BY W/LL/AM H. THYS ATToF/YEY p l 1957 J. F. KIRBY ET AL 2,787,956

PRINTING PLATE CYLINDER AND METHOD OF MOUNTING OR DEMOUNTING SAME FROM A MANDREL. Filed July 28, 1953 2 Sheets-Sheet 2 I23 INVENTORS JOHN F. KIRBY WILLIAM H. THYS W ATTORNE PRINTING PLATE CYLINDER AND METHOD OF MOUNTING 0R DEMOUNTING SAME FROM A MANDREL John F. Kirby, Baldwin, and William H. Iliys, Arvenie, N. Y., assiguors to Mosstype Roller Co., Inc., New York, N. Y., a corporation of New York Application July 28, 1953, Serial No. 370,797 7 Claims. (Cl. 101-375) damaging the cylinder or mandrel, and which can" be quickly and easily replaced on the mandrel, or on the mandrel of another printing press, with all of its original accuracy, so as to provide maximum "versatility of use for each cylinder.

It is still another object of the present invention to provide 'a highly improved printing cylinder which is economical in construction, and which can be readily removed from the mandrel of a printing press and stored for future use.

It is a further object of the present invention to provide a highly improved printing cylinder which issiniplin construction and durable in operation, which is eliedti'v'e for its intended purposes, and which can be manufactured and sold at a reasonable cost.

Other features and objects of the invention reside'in the particular construction, combination and arrangement of parts, and in the novel steps and arrangements of steps hereinafter described in connection with the accompanying drawings, forming a material art hereof, and illustratin'g various embodiments of the invention.

In the drawings:

Fig. 1 is a front elevational view, partly in setion, showing a printing cylinder constructed inaceordanee with the present invention. I

Fig. 2 is a front elevational view, partly in section, showing a slightly modified form of the present invention.

Fig. 3 is a front elevational view, partly in section, showing another slightly modified form of the present invention.

Fig. 4 is a front elevational view, partly in section,

showing still another slightly modified form of the present invention.

Fig. 5 is a front elevational view, partly in s'e'etin, showing still another slightly modified form of the present invention.

Fig. 6 is a front elevationalview,- 'paftl y' in setion,

showing yet a further modification 'of the present invention.

Fig. 7 is a front elevational view, partly resection,

showing the cylinder of Fig. 1 being placed upon or removed from the mandrel ofa printing press.

Fig. 8 is a longitudinal sectional view of still another form of. the invention.

Fig. 9 is a longitudinal sectional view ofanother-modifiheating units to shoulders" of printing 'eyiindersi Fig. 12 is an end view of Fig. 13.

nited States Patent 0 ice Fig. '13 is a fragmentary view partly in section, taken on the line 13+1-3 of Fig. 12, and showing manner of insuring fixed relation between printing cylinder and the mandrel.

Referring now more particularly to the drawings, and specifically to Fig. l, the embodiment of the invention illustrated therein comprises a printing cylinder, generally designated 10, mounted on a mandrel or shaft 11 of a printing press.

The cylinder 10 includes a tubular member 12, relatively thin walled, and having its opposite ends closed, as by end closures 13 The end closures 13 may he formed integrally with the tubular member 12, as shown in Fig. l, of fabricated separately and fixedly secured to the tubular member by any suitable means, such as welding, etc. Each of the end closures 13 is provided with a through bore 14 coaxially of the tubular member 12 and of a diameter slightly less than the diameter of mandrel 11. Thus, it is necessary to shrink fit the cylinder 1.0 on mandrel 11. That is, the end closures 13 are heated, and expand so as to receive the mandrel 11, and upon cooling contract to firmly grip the mandrel. An important feature of the present invention resides in the thermal coetiicient of expansion of the material employed in the fabrication of end closures 13. It is important that the thermal coefficient of expansion of the end closures 13 be high with respect to the thermal coefficient of expansion of mandrel 11, for a purpose appearing hereinafter.

When it is desired to remove the cylinder 10 from the mandrel 11, it is only necessary 'to heat the end closures 13 to expand the latter with respect to the mandrel 11. That is, heat applied to the end closures 13 will effect expansion thereof, causing the end closures to release the mandrel and permit free sliding movement'of the end closures along the mandrel. While heat may be conducted through the end closures 13 to the mandrel 11, the expansion of the end closures is substantially greater than that of the mandrel to eiiect expansion of the end closures relative to the mandrel. This operation is illustrated in Fig. 7, wherein a pair of annular, discshaped heating units 15 are disposed in face-to-face abutting engagement with respect to the end surfaces of end closures 13, and held in abutting engagement by a clamp 16. The heating units 15 each include a casing 17, electric heating coils 18 disposed within the casing, and means 19 for connection to a source of electric supply.

Thus, when it is desired to place the cylinder 10 upon the mandrel 11, the heating units 15 are positioned in abutting relation with respect to opposite ends'of the cylinder and held in said relation by the clamp 16, or other suitable means, some illustrations of which will appear hereinafter. Electric current is caused to pass through the heating coils or elements 18 to effect thermal expansion of the end closures 13, and consequently of the bore 14. The mandrel 11 may then be slidingly inserted through the bores 14- and the heating units 15 removed to permit cooling and contraction of the end closures 13 and bores 14. Thus, the cylinder 10 is shrunk on the mandrel 11. Similarly, the cylinder 10 may be removed from the mandrel 11 by heating the end closures 13 to expand the same and sliding the cylinder off the mandrel. It will be noted that the concentricity of the cylinder 16 with respect to the mandrel 11 is determined by co'ncentricity of the bores 14 and if the concentricity of the cylinder is accurate when first placed on the mandrel 1-1, the cylinder may be removed and replaced withall of its original accuracy. In practice, it has been found satisfactory to fabricate the cylinder 10 of magnesium 'for'its relatively high thermal jcoeliicie'nt (if expansion, lightness of weight, and strength. It will be noted that the tubular member 12 is relatively thin walled, having an internal diameter substantially greater than the diameter of mandrel 1 thereby effecting considerable savings in materials and reduction in weight.

In Fig. 2 is shown a slightly modified form of cylinder,

generally designated 20. The cylinder 20 includes a tubular member 21 having end closures 22 which are formed with reduced outer portions 23 providing outwardly facing shoulders 24. The end closures 22 are formed with central, internal recesses 25 in order to reduce the area of contact between the end closures and mandrel 11. The

.shoulders 24 and reduced portion 33 provide means for mounting annular heating units 26. The heating units 26 are removably seated on the shoulders 24, or may be permanently mounted thereon, and include an annular casing 27, electric heating coils 28, and means 29 for connection to a source of electric current. As described in connection with Fig. l, the heating units 26 are employed to effect relative expansion of the end closures 22 with respect to the mandrel 11 to shrink lit the cylinder on the mandrel and to efiiect removal of the cylinder from the mandrel.

In Fig. 3 is shown another slightly modified form of the present invention, wherein cylinder 30 comprises a tubular member 31 having end closures 32 adjacent its opposite ends. The end closures 32 are formed with annular channels 33 extending inwardly from the outer surfaces 34 of the end closures. The channels or grooves 33 are adapted to removably seat annular heating elements, such as described in connection with Fig. 2. The operation of the device illustrated in Fig. 3 is the same as described hereinbefore in connection with Figs. 1 and 2.

In Fig. 4 is shown still another slightly modified form of the present invention, wherein a cylinder 40 is fabricated of a tubular member 4 and oppositely disposed plugs or end closures 42. The tubular member 41 has internally enlarged end portions 43 terminating at internal shoulders 44, for seating the plugs or end closures 42. The plugs or end closures 42 are formed with annular peripheral grooves or channels 45 which are adapted to seat the heating elements 46, and combine with the tubular member 41 to completely enclose the heating units.

The plug 42 is fixedly secured to the tubular member 41 'and provided with an electric socket 47 for connecting the heating unit 46 to a source of electric current. While the plug 42 and the tubular member 51 may be fabricated of different materials, it is essential that the plug be fabricated of a material having a relatively high coefiicient of thermal expansion with respect to that of the mandrel 11, for reasons appearing hereinbefore. In operation, the cylinder 40 may be placed upon and removed from the mandrel 11 in the same manner as the foregoing forms of the resent invention.

In Fig. is shown a further slightly modified form of the present invention, wherein the cylinder 50 comprises a tubular member 51 and plugs or end closures 52. The tubular member 51 is provided with internally enlarged end portion 53 terminating in annular, internal shoulders 54. Seated on the shoulders 54 are annular heating units 55, spaced from the mandrel 11 as at 56, and held in position by the plugs 52. That is, the plugs 52 are fixedly secured in the enlarged tubular member portion 53 in abutting engagement with the heating units 54. Electrical wiring 57 extends through the plug 52 from the heating unit 55 to a socket 58 mounted in the plug and adapted to connect the heating unit to a source of electric current. In operation, the modification of Fig. 5 is the same as that of the hereinbefore described modifications. Under certain printing conditions, it may be desirable to employ the present invention in connection with a sectional cylinder such as is designated 60 in Fig. 6. The

' sectional cylinder 60 comprises cylinder parts 61 and 62 disposed in end-to-end aligned relation with respect to each other. Cylinder part 61 includes a tubular memiber 63 having a plug 64 fixedly secured in one end, the

4. plug 64 being formed with an axial bore 65 adapted to slidably receive the mandrel 11. Partially inserted in the other end of tubular member 63 is a plug 66 having its inner end recessed as at 6'7 and fixedly secured to the tubular member 63 by any suitable means. The plug 66 is formed with an axial bore 68 having a diameter slightly less than the diameter of mandrel i1 and has one end 69 extending beyond the adjacent end of tubular member 63 to form a shoulder 70. Removably seated on the extended portion of plug 66 is a heating unit 71 in abutting engagement with the shoulder or end 70 of tubular mem ber 63 and adapted to heat the plug 66 to expand the same. Cylinder part 62 is identical to cylinder part 61 and is provided with a shoulder 73 for removably mounting a heating unit 74. The cylinder parts 61 and 62 are keyed together as at 75 to maintain proper alignment and spacing with respect to each other. In operation, the cylinder parts 61 and 62 are substantially the same as described hereinbefore, the parts being mounted upon and removed from the mandrel 11 separately or together, as desired.

In Fig. 8 is shown another modification of the present invention wherein a cylinder includes a tubular member 81 and plugs or end closures 82 and 83. The end closures 82 and 83 are provided with coaxial through bores 84 and 85 which are preferably tapered, for reasons appearing presently. A mandrel 86 is formed with spaced annular, or peripheral shoulders or hands 87 and 88, which are slightly larger than the bores 84 and 85, respectively, and tapered conformably with respect to the bores. The shoulders or bands 87 and 38 may be provided with peripherally extending annular grooves 89 and 90, for reasons which will soon become apparent. Thus, when the end closures 82 and 83 are expanded by application of heat, the cylinder 80 may be quickly and easily circumposed about the handrel 86 by moving the cylinder from left to right, that is, from the smaller mandrel end to the larger. It will be apparent, that the annular grooves 89 and 90, which may, of course, be other than annular, serve to limit or minimize the heat transmitted from the end closures 82 and 83 to the shoulders or bands 87 and 88, thereby substantially reducing or eliminating any distortion of the mandrel.

In Fig. 9 is shown another slightly modified form of the present invention, wherein the cylinder 92 comprises a tubular member 93 and plugs or end closures 94, 94. Each of the end closures is provided with a coaxial, through bore 95. In this form of the present invention, it is not essential that the end closures 94 or tubular member 93 be fabricated of material having a high thermal coefiicient of expansion, but rather, it is preferred to "employ material having a relatively low coefficient of thermal expansion.

The mandrel 96 is preferably hollow, for reasons which will become apparent hereinafter. Adjacent to opposite ends of the mandrel 96 and circumposed thereabout are a pair of bands or annular shoulders 97, 97 which are preferably fabricated of material having a relatively high coeflicient of thermal expansion. As the diameter of the bands or shoulders 97 is slightly greater than the internal diameter of the bores 95, it is apparent that the shoulders may be reduced by cooling to permit insertion into the bores and permitted to expand upon return to room temperature, to thereby elfect a tight and firm fit. It has been found desirable to form the mandrel 96 hollow so as to permit the passage therethrough of a cooling medium;

In Figs. 10 and 11 is illustrated another manner of holding a heating element adjacent to the cylinder end.

The-hollow cylinder 100 has its opposite ends identical, so that the fragmentary or partial showing in Fig. 11 will sufiice. In each end of the cylinder 100 is a plug or end closure 101 which is formed with a coaxial, through bore 102. A nipple 103 projects outwardly from the end closure 101 and is in'alignment with the bore 102. Ex-

tending peripherally about the nipple 103 -is an annular groove 104; and, arcuate or segmental notches 105 extend inwardly from the projecting end of the nipple 103 and open into the groove 104. A cup-like retaining member 106 is removably circumposed about the nipple 103 and includes an annular plate 107 having circumferentially spaced arcuate notches 108 formed on its inner edge and defining therebetween tabs 109. Extending along the outer 'edge of the plate 107 is a lateral flange 110 which combines with the plate 107 to define a cuplike member. Seated within the cup-like member 107 is an annular ring of insulating material 112 which supports an annular heating element 113. It will now be apparent that the cup-like member 107, including the heating elemtnt 113, may be circumposed about the cylinder nipple 103 by movement of the tabs 109 through the notches 105 into the groove 104. The heating element 113 will then abut the outer face of the end closure 101 and the cup-like member 107 may be rotated so as to engage the tabs 109 with the inner surface of the groove 104. As any suitable insulating material 112 may be employed, it is seen that the heating element 113 will be maintained in abutting engagement with the end closure 161. Of course, the cup-like member 107 may be removed by simply rotating the same so as to position the tabs 109 adjacent to the grooves or notches 108 and moving the cup-like member toward the left, as viewed in Fig. 11.

in Figs. 12 and 13 are shown an additional means for insuring the fixed relation between the printing cylinder and mandrel. The cylinder 120 is substantially identical on both ends so that a detailed description of one end will sufiice. The cylinder 120 includes a plug or end closure 121 which is formed with a coaxial through here 122. The outer end closure face 123 is recessed at spaced points 124 and 125 for purposes soon to become apparent. A mandrel 126 includes a peripheral shoulder or band 127 adjacent to each end, which bands are preferably grooved as at 128, for reasons previously described. The enlarged shoulder or band construction of the mandrel has been found preferable even where the cylinder end closure is to be expanded and contracted, as the lesser mandrel diameter with respect to that or" the heads permits easy mounting and demounting of the printing cylinder.

The mandrel end portions are reduced as at 129 and a collar or annular ring 130 is removably circumposed about the reduced mandrel portion and in abutting engagement with the outer surface 123 of the cylinder end closure 121. A set screw 131 extends radially inwardly through the collar 130 and into engagement with the mandrel portion 129 for fixedly securing the collar to the mandrel. The collar is provided with lateral projections or pins 132 and 133 which extend into the recesses 124 and 125. As the collar is fixed to the mandrel and in abutting engagement with the cylinder ends, it is apparent that the longitudinal movement of the coller is constrained; and, as the pins 132 and 133 are fixed to the collar 130, it is apparent that circumferential movement of the cylinder is also prevented.

From the foregoing, it is apparent that the present invention provides a printing cylinder which is adapted to be readily removed from and replaced upon a mandrel with all its original accuracy, and which is well adapted to meet conditions of practical use.

In general, it will be understood that those skilled in the art may readily make changes in the details herein described and illustrated, without necessarily departing from the spirit and scope of the invention as expressed in the appended claims.

What we claim as new and desire to secure by Letters Patents, is:

1. In combination a mandrel and a replaceable printing cylinder removably shrunk on said mandrel, said printing cylinder comprising a hollow tubular member diameter of said mandrel, end closures fixedly secured on opposite ends of said tubular member and each having a through bore of a diameter slightly less than the diameter of said mandrel, said bores being coaxial and said end closures being fabricated of material having a relatively high coefiicient of thermal expansion with respect to said mandrel, and means on said end closures for thermally expanding said end closures for selectively effecting shrink fitting of the same on said mandrel, and for releasing the same therefrom.

2. In combination, a mandrel and a removable and replaceable printing cylinder thereon, said printing cylinder comprising a tubular member, the outer cylindrical surface of which is capable of having printing plates removably secured thereon, end closures fixedly secured on opposite ends of said tubular member and each having a coaxial through bore of a diameter slightly less than the diameter of said mandrel, said end closures and tubular member being fabricated of material having a relatively high coeflicient of thermal expansion with respect to said mandrel, and each end closure being formed with an annular channel, and an annular heating unit removably seated in said channel, whereby said end closures are thermally expanded for eifecting shrink fitting of said end closures on said mandrel and thermally expanded for releasing the same therefrom.

3. The method of assembling and disassembling printing cylinder and a supporting mandrel, which method comprises providing a printing cylinder having a hollow tubular member and end closures fabricated of material having a relatively high coefficient of thermal expansion with respect to that of a mandrel with which the printing cylinder is to be assembled, forming a through axial bore in each of said end closures of a diameter slightly less than that of said mandrel, thermally expanding said end closures to a diameter larger than that of the mandrel by the application of heat thereto, then selectively introducing a mandrel into or removing the mandrel from said axial bores and discontinuing the heat, permitting the end closures to cool and thus contract.

4. The method of removably securing a printing cylinder on a mandrel, which method comprises: providing a printing cylinder comprising a hollow tubular member and end closures fabricated of material having a relatively high coefiicient of thermal expansion with respect to that of a mandrel on which the printing cylinder is to be secured, forming a through axial bore in said end closures of a diameter slightly less than that of said mandrel, applying a heating element in heat transfer relation to each of said end closures, then thermally expanding said end closures by energizing said heating elements, then introducing a mandrel into said axial bores, discontinuing the heat and permitting the end closures to shrink tightly about said mandrel.

5. The method of removably securing a printing cylinder on a mandrel, which method comprises: providing a printing cylinder comprising a hollow tubular member and end closures fabricated of material having a relatively high coefiicient of thermal expansion with respect to that of a mandrel on which the printing cylinder is to be secured, forming a through axial bore in said end closures of a diameter slightly less than that of said mandrel, thermally expanding said end closures by the application of heat thereto, introducing said mandrel into said axial bores, discontinuing the application of heat and permitting the end closures to cool to shrink tightly about said mandrel.

6. In combination, a mandrel and a removable and replaceable printing cylinder thereon, said printing cylin der comprising a tubular member, the outer cylindrical surface of which is capable of having printing plates removably secured thereon, end closures fixedly secured on opposite ends of said tubular member and each having a coaxial through bore of a diameter slightly less than the diameter of' said mandrel, said 'end closures being fabricated of material having a relatively high coeflicient of thermal expansion with respect to said mandrel, a heating element disposedupon each end of the printing cylinder, whereby said end closures may be thermally expanded by the application of heat thereto for selectively assembling and disassembling the mandrel and the printing cylinder.

7. In combination, a steel mandrel and a replaceable magnesium printing cylinder removably shrunk on said mandrel, said printing cylinder comprising a tubular memher and end closures fixedly secured on opposite ends of said tubular member and each having a coaxial through bore of a diameter slightly less than the diameter of said mandrel, said end closures being fabricated of magnesium, and heating means removably applied to each said end closure, whereby said end closures may be thermally expanded for elfecting shrink fitting of Said end closures on said mandrel when they are to be assembled, and thermally expanded for releasing the mandrel from the end closures when they are to be disassembled.

References Cited in the file of this patent UNITED STATES PATENTS 196,149 Hope Oct. 16, 1877 1,047,206 Grignard Dec. 17, 1912 1,497,223 Moodie June 10, 1924 1,787,187 Brueshaber Dec. 30, 1930 1,817,808 Eaton Aug. 4, 1931 1,995,973 Ericksson Mar. 26, 1935 2,168,233 Millspaugh Aug. 1, 1939 2,671,262 Kuniholm Mar. 9, 1954 

